With the nights drawing in and clocks about to go back, it may seem a crazy time to consider installing solar power to your house.

But with oil prices soaring by 66 per cent and British Gas hiking charges twice during the last year, tapping into a source that in one day provides enough energy to fuel the world for a year doesn't seem quite so daft.

Photovoltaic (PV) panels bolted on your roof soak up sunlight and generate electricity. The amount generated depends on the size of the panel, its position and the time of year, but one measuring between 10 and 20 square metres would produce 30 per cent to 50 per cent of a typical family's needs. Any extra power needed by the household can be drawn as normal from the National Grid, and any excess produced by the PV panels can be fed into the grid and set against the household's electricity bills.

Because the use of panels reduces the emission of CO2 compared to electricity generated through conventional methods, the government offers grants worth up to half the installation cost. To qualify for a grant, the panel must be fitted by an installer accredited by the Energy Savings Trust. Even so the panels are not cheap, costing from £5,000 to install.

David Eldridge, a pensioner, installed a PV panel costing £9,000 including grant two years ago, and has not had to pay for electricity since. In fact, he has made a net profit of about £70 a year. But he estimates it will still take 20 years to recoup the cost.

He is also employing energy efficiency measures, such as turning off his freezer. 'I've decided to shop more frequently and use my fridge for storage, which hasn't been too inconvenient.' He has two electricity meters - one showing how much he has taken from the National Grid, and the other how much he has contributed. His electricity supplier pays him for any electricity he feeds into the grid at the same rate he is charged for the electricity it supplies to him.

'The normal meter is read in the conventional way, and I supply readings on a monthly basis for the electricity I supply to my electricity company. It then sends me a payment every three months,' he says.

Homeowners who are unable to install a panel because they live in a conservation area or their house is listed can now opt for PV tiles instead. These come in a range of colours to blend in with your existing tiles.

Steff Wright, a builder from Lincolnshire, has installed PV tiles in his home for a cost of £8,000, with half paid by a government grant.

He estimates he will recoup the cost in 10 to 15 years. 'But it depends on how electricity goes up in price - it could be sooner. As energy prices go up, people will see that it makes sense.

'But the real payback is the fact that these tiles create electricity without creating CO2.'

Grants summary

You can apply for a grant towards the cost of PV equipment and installation by applying online at www.est.org.uk/ solar or calling the EST solar helpline on 0800 298 3978. Business and social housing groups can also get grants.

How to keep the bills down:

· Use a laptop instead of a PC

· Switch off and unplug chargers for mobiles, toothbrushes and laptops after use

· Turn off your gadgets altogether - don't leave on standby as it uses nearly as much electricity as having the gadget switched on

· Install a consumption or energy display metre so you can see how much electricity you are using and which gadgets use the most.

· Consider getting rid of your freezer

· Replace worn-out white goods with A-rated appliances - these are the most energy efficient. The same energy ratings will soon be extended to brown goods

· Connect all your computer-related gadgets to a One Click intelligent mains panel, which allows you to turn off all the gadgets with one flick of the switch rather than leaving most on standby. One Click Technologies estimates its IMP saves £700 over its lifetime. Buy at a discount from Powergen for £18.49. Call 0845 3309910.

WIN A SOLAR POWER SYSTEM FOR YOUR HOUSE

The Energy Saving Trust (EST) is offering one lucky reader the chance to win a Solarcentury sunstation, powered by Sanyo, worth £8,000.